/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/HttpConnectionManager.java,v 1.24 2004/07/05 22:46:58 olegk Exp $
 * $Revision: 480424 $
 * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
 *
 * ====================================================================
 *
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.commons.httpclient;

import org.apache.commons.httpclient.params.HttpConnectionManagerParams;

/**
 * An interface for classes that manage HttpConnections.
 * 
 * @see org.apache.commons.httpclient.HttpConnection
 * @see org.apache.commons.httpclient.HttpClient#HttpClient(HttpConnectionManager)
 * 
 * @author Michael Becke
 * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
 * @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
 * 
 * @since 2.0
 */
public interface HttpConnectionManager {

	/**
	 * Gets an HttpConnection for a given host configuration. If a connection is
	 * not available this method will block until one is.
	 * 
	 * The connection manager should be registered with any HttpConnection that
	 * is created.
	 * 
	 * @param hostConfiguration
	 *            the host configuration to use to configure the connection
	 * 
	 * @return an HttpConnection for the given configuration
	 * 
	 * @see HttpConnection#setHttpConnectionManager(HttpConnectionManager)
	 */
	HttpConnection getConnection(HostConfiguration hostConfiguration);

	/**
	 * Gets an HttpConnection for a given host configuration. If a connection is
	 * not available, this method will block for at most the specified number of
	 * milliseconds or until a connection becomes available.
	 * 
	 * The connection manager should be registered with any HttpConnection that
	 * is created.
	 * 
	 * @param hostConfiguration
	 *            the host configuration to use to configure the connection
	 * @param timeout
	 *            - the time (in milliseconds) to wait for a connection to
	 *            become available, 0 to specify an infinite timeout
	 * 
	 * @return an HttpConnection for the given configuraiton
	 * 
	 * @throws HttpException
	 *             if no connection becomes available before the timeout expires
	 * 
	 * @see HttpConnection#setHttpConnectionManager(HttpConnectionManager)
	 * 
	 * @deprecated Use #getConnectionWithTimeout(HostConfiguration, long)
	 */
	HttpConnection getConnection(HostConfiguration hostConfiguration,
			long timeout) throws HttpException;

	/**
	 * Gets an HttpConnection for a given host configuration. If a connection is
	 * not available, this method will block for at most the specified number of
	 * milliseconds or until a connection becomes available.
	 * 
	 * The connection manager should be registered with any HttpConnection that
	 * is created.
	 * 
	 * @param hostConfiguration
	 *            the host configuration to use to configure the connection
	 * @param timeout
	 *            - the time (in milliseconds) to wait for a connection to
	 *            become available, 0 to specify an infinite timeout
	 * 
	 * @return an HttpConnection for the given configuraiton
	 * 
	 * @throws ConnectionPoolTimeoutException
	 *             if no connection becomes available before the timeout expires
	 * 
	 * @see HttpConnection#setHttpConnectionManager(HttpConnectionManager)
	 * 
	 * @since 3.0
	 */
	HttpConnection getConnectionWithTimeout(
			HostConfiguration hostConfiguration, long timeout)
			throws ConnectionPoolTimeoutException;

	/**
	 * Releases the given HttpConnection for use by other requests.
	 * 
	 * @param conn
	 *            - The HttpConnection to make available.
	 */
	void releaseConnection(HttpConnection conn);

	/**
	 * Closes connections that have been idle for at least the given amount of
	 * time. Only connections that are currently owned, not checked out, are
	 * subject to idle timeouts.
	 * 
	 * @param idleTimeout
	 *            the minimum idle time, in milliseconds, for connections to be
	 *            closed
	 * 
	 * @since 3.0
	 */
	void closeIdleConnections(long idleTimeout);

	/**
	 * Returns {@link HttpConnectionManagerParams parameters} associated with
	 * this connection manager.
	 * 
	 * @since 3.0
	 * 
	 * @see HttpConnectionManagerParams
	 */
	HttpConnectionManagerParams getParams();

	/**
	 * Assigns {@link HttpConnectionManagerParams parameters} for this
	 * connection manager.
	 * 
	 * @since 3.0
	 * 
	 * @see HttpConnectionManagerParams
	 */
	void setParams(final HttpConnectionManagerParams params);
}
